问题描述
我在新项目中使用 Spring + Redis 作为缓存组件.spring配置xml文件为:
I am using Spring + Redis as my cache component in the new project. The spring config xml file is:
<!-- Jedis Connection -->
<bean id="jedisConnectionFactory"
class="org.springframework.data.redis.connection.jedis.JedisConnectionFactory"
p:host-name="${redis.ip}" p:port="${redis.port}" p:use-pool="${redis.use-pool}" />
<!-- Redis Template -->
<bean id="redisTemplate" class="org.springframework.data.redis.core.RedisTemplate">
<property name="connectionFactory" ref="jedisConnectionFactory" />
<property name="keySerializer">
<bean class="org.springframework.data.redis.serializer.StringRedisSerializer" />
</property>
<property name="valueSerializer">
<bean class="org.springframework.data.redis.serializer.JdkSerializationRedisSerializer" />
</property>
</bean>
<bean id="cacheManager" class="org.springframework.data.redis.cache.RedisCacheManager" c:template-ref="redisTemplate"/>
<cache:annotation-driven mode="proxy" proxy-target-class="true" cache-manager="cacheManager" />
用法是
@Cacheable(value = "cacheManager", key="#userId")
public User getUser(String userId) {
System.out.println("execute==");
return userAdminMapper.getUser(userId);
}
我的测试用例是:
@Test
public void testCacheUser2() {
String id = "test";
User user = userService.getUser(id);
System.out.println(user);
user.setUserCreateDate(new Date());
userService.updateUser(user);
User user2 = userService.getUser(id);
System.out.println(user2);
User user3 = userService.getUser(id);
System.out.println(user3);
}
如果Redis服务器正在运行，则代码运行正确.但我的问题是，如果我关闭 Redis 服务器，它会抛出异常:
If the Redis server is running, the code is running correctly. But my question is if I shutdown the Redis server, it will throw the exception:
org.springframework.data.redis.RedisConnectionFailureException: Cannot get Jedis connection; nested exception is redis.clients.jedis.exceptions.JedisConnectionException: java.net.ConnectException: Connection refused: connect
at org.springframework.data.redis.connection.jedis.JedisConnectionFactory.fetchJedisConnector(JedisConnectionFactory.java:140)
at org.springframework.data.redis.connection.jedis.JedisConnectionFactory.getConnection(JedisConnectionFactory.java:229)
at org.springframework.data.redis.connection.jedis.JedisConnectionFactory.getConnection(JedisConnectionFactory.java:57)
at org.springframework.data.redis.core.RedisConnectionUtils.doGetConnection(RedisConnectionUtils.java:128)
at org.springframework.data.redis.core.RedisConnectionUtils.getConnection(RedisConnectionUtils.java:91)
at org.springframework.data.redis.core.RedisConnectionUtils.getConnection(RedisConnectionUtils.java:78)
at org.springframework.data.redis.core.RedisTemplate.execute(RedisTemplate.java:177)
at org.springframework.data.redis.core.RedisTemplate.execute(RedisTemplate.java:152)
at org.springframework.data.redis.cache.RedisCache.get(RedisCache.java:87)
at org.springframework.cache.interceptor.CacheAspectSupport.findInCaches(CacheAspectSupport.java:297)
at org.springframework.cache.interceptor.CacheAspectSupport.findInAnyCaches(CacheAspectSupport.java:287)
at org.springframework.cache.interceptor.CacheAspectSupport.collectPutRequests(CacheAspectSupport.java:266)
at org.springframework.cache.interceptor.CacheAspectSupport.execute(CacheAspectSupport.java:199)
at org.springframework.cache.interceptor.CacheAspectSupport.execute(CacheAspectSupport.java:178)
at org.springframework.cache.interceptor.CacheInterceptor.invoke(CacheInterceptor.java:60)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:98)
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:262)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:95)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:644)
at sg.infolab.common.admin.service.impl.UserServiceImpl$$EnhancerBySpringCGLIB$$c7f982a7.getUser(<generated>)
at sg.infolab.admin.test.RedisServiceTest.testCacheUser2(RedisServiceTest.java:35)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:74)
at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:83)
at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:72)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:232)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:89)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:71)
at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:175)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
Caused by: redis.clients.jedis.exceptions.JedisConnectionException: java.net.ConnectException: Connection refused: connect
at redis.clients.jedis.Connection.connect(Connection.java:150)
at redis.clients.jedis.BinaryClient.connect(BinaryClient.java:71)
at redis.clients.jedis.BinaryJedis.connect(BinaryJedis.java:1783)
at org.springframework.data.redis.connection.jedis.JedisConnectionFactory.fetchJedisConnector(JedisConnectionFactory.java:137)
... 50 more
Caused by: java.net.ConnectException: Connection refused: connect
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:351)
at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:213)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:200)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
at java.net.Socket.connect(Socket.java:529)
at redis.clients.jedis.Connection.connect(Connection.java:144)
... 53 more
请问客户端连接不上Redis Server，为什么会抛出异常?我们可以这样配置场景吗——如果缓存层(Redis Server)无法连接(可能是崩溃或网络不通)，它应该直接连接到数据库并获取数据.
I want to ask if the client couldn't connect Redis Server, why will it throw exception? Can we config the scenario like this -- if the cache layer(Redis Server) cannot connect(maybe it is crashed or network is not up), it should directly connect to database and fetch data.
推荐答案
我遇到了同样的问题.我正在针对数据库开发一些数据服务，通过 Spring Caching 注释使用 Redis 作为缓存存储.如果 Redis 服务器变得不可用，我希望服务像未缓存一样继续运行，而不是抛出异常.
I had the very same problem. I'm developing some data services against a database, using Redis as the cache store by way of Spring Caching annotations. If the Redis server becomes unavailable, I want the services to continue to operate as if uncached, rather than throwing exceptions.
一开始我尝试了一个自定义的CacheErrorHandler，这是Spring提供的一种机制.它不太好用，因为它只处理 RuntimeExceptions，并且仍然让 java.net.ConnectException 之类的事情搞砸了.
At first I tried a custom CacheErrorHandler, a mechanism provided by Spring. It didn't quite work, because it only handles RuntimeExceptions, and still lets things like java.net.ConnectException blow things up.
最后我所做的是扩展 RedisTemplate，覆盖一些 execute() 方法，以便它们记录警告而不是传播异常.这看起来有点像 hack，我可能重写了太少的 execute() 方法或太多，但它在我所有的测试用例中都很有效.
In the end what I did is extend RedisTemplate, overriding a few execute() methods so that they log warnings instead of propagating exceptions. It seems like a bit of a hack, and I might have overridden too few execute() methods or too many, but it works like a charm in all my test cases.
不过，这种方法有一个重要的操作方面.如果 Redis 服务器变得不可用，您必须在使其再次可用之前刷新它(清除条目).否则，您可能会开始检索由于同时发生的更新而包含不正确数据的缓存条目.
There's an important operational aspect to this approach, though. If the Redis server becomes unavailable you must flush it (clean out the entries) before making it available again. Otherwise there's a chance that you might start retrieving cache entries that have incorrect data because of updates that occurred in the meantime.
以下是源码.随意使用它.希望能帮到你.
Below is the source. Feel free to use it. I hope it helps.
import java.util.List;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.data.redis.core.RedisCallback;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.SessionCallback;
import org.springframework.data.redis.core.script.RedisScript;
import org.springframework.data.redis.serializer.RedisSerializer;
/**
* An extension of RedisTemplate that logs exceptions instead of letting them propagate.
* If the Redis server is unavailable, cache operations are always a "miss" and data is fetched from the database.
*/
public class LoggingRedisTemplate<K, V> extends RedisTemplate<K, V> {
private static final Logger logger = LoggerFactory.getLogger(LoggingRedisTemplate.class);
@Override
public <T> T execute(final RedisCallback<T> action, final boolean exposeConnection, final boolean pipeline) {
try {
return super.execute(action, exposeConnection, pipeline);
}
catch(final Throwable t) {
logger.warn("Error executing cache operation: {}", t.getMessage());
return null;
}
}
@Override
public <T> T execute(final RedisScript<T> script, final List<K> keys, final Object... args) {
try {
return super.execute(script, keys, args);
}
catch(final Throwable t) {
logger.warn("Error executing cache operation: {}", t.getMessage());
return null;
}
}
@Override
public <T> T execute(final RedisScript<T> script, final RedisSerializer<?> argsSerializer, final RedisSerializer<T> resultSerializer, final List<K> keys, final Object... args) {
try {
return super.execute(script, argsSerializer, resultSerializer, keys, args);
}
catch(final Throwable t) {
logger.warn("Error executing cache operation: {}", t.getMessage());
return null;
}
}
@Override
public <T> T execute(final SessionCallback<T> session) {
try {
return super.execute(session);
}
catch(final Throwable t) {
logger.warn("Error executing cache operation: {}", t.getMessage());
return null;
}
}
}
这篇关于Spring Redis 错误句柄的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！